The present invention relates to a thermal transfer type of image recording apparatus for recording a color image with an image recording means comprising a thermal head and a thermal transfer type of ink ribbon in an image recording medium wound around a platen drum based on image data recorded in an image data recording means or transmitted through a communication means and also relates to a thermal transfer type of ink ribbon and a thermal transfer type of ink ribbon cassette used in this image recording apparatus.
A conventional type of image recording apparatus is shown in FIG. 1. The image recording apparatus shown in FIG. 1 comprises a thermal transfer type of ink ribbon 500, an image recording medium 501, a platen drum 502, a thermal head 503, a damper 504, a platen drum driving motor 505, and a recording medium hopper 506. A contact section between the damper 504 and the recording medium 501 is covered with a frictional member 509 such as rubber adhered thereto. In FIG. 1, the thermal head 503, a thermal transfer type of ink ribbon 500, recording medium 501, and platen drum 502 are arranged in this order. The thermal transfer type of ink ribbon 500 is colored with different colors cyclically and a wound around in the feeder core 507 in a rolled form, and is wound up around a winder core 508 in the opposite side. For instance, the three colors of yellow, magenta, and cyan form one group. In some ribbons, black or a transparent overcoat material for coating the surface is added to the three colors described above. The following description of operations assumes a three-color ribbon. At first, a header section of the thermal transfer type of ink ribbon 500 with a given color is positioned at the starting position. Then the recording medium 501 is carried from the recording medium hopper 506 to the damper 504 and is wound around the platen drum 502. Then recording medium 501 carried thereto is held between the platen drum 502 and damper 504 each loading a pressure thereto to hold it. The a rear surface of the damper 504, namely a section contacting the recording medium 501 is made from a frictional member 509 such as rubber, and holds the recording medium 501 by means of the frictional force. When the recording medium 501 is firmly held, the thermal head 503 is moved to the platen drum 502 and a pressure is loaded to the thermal head 503 so that the thermal transfer type of ink ribbon 500 and recording medium 501 are closely adhered to each other. Then the platen drum driving motor 505 rotates with the thermal head 503 energized and heated in synchronism to start of rotation thereof according to an arbitrary dot so that the heated color material is transferred from the thermal transfer type of ink ribbon 500 onto the recording medium 501 and an image is formed thereon. After processing with the first color is finished, the thermal head 503 releases the pressure, moves away from the platen drum 502, and feeds the thermal transfer type of ink ribbon 500 to position a section with the next color at its starting position with the platen drum 502 rotating in the image-forming direction to position the recording medium 501 at its starting position. Further, the same operations as those described above are repeated to form a image for a next color, and thus the operation sequence is repeated required times to form a color image.
The most important requirement in this operation sequence is that positioning of the recording medium 501 at its starting position is performed by controlling a position of the platen drum 502. Therefore, to prevent change in a positional relation between the platen drum 502 and the recording medium 501 to be wounded therearound for each color, the platen drum 502 and the recording medium 501 are held by such a tool as the damper 504 with the frictional member 509 such as rubber adhered thereto.
In the conventional type of image recording apparatus as described above, recording medium 501 are fed one by one from the recording medium hopper 506 to the platen drum 502, and a header section of this recording medium 501 is clamped by the damper 504 to the platen drum 502 with a rear edge section of the recording medium 501 held by a pinch roller between the pinch roller and the platen drum 502. Because of this configuration, a load by the pinch roller gives effects over the platen drum 502 so that a driving load for the platen drum 502 disadvantageously increases.
In some of the image recording apparatuses based on the conventional technology, the recording medium 501 are not fed one by one, and the recording medium wound up into a roll form is cut into sheets, which are fed one by one. In this roll system, the recording medium 501 fed out from a roll is cut into a sheet of recording medium 501, which is wound around the platen drum 502, and then an image is recorded on this recording medium 501 with the thermal head 503 and thermal transfer type of ink ribbon 500, and when the recording medium 501 with the image recorded thereon is to be discharged, the platen drum 502 is rotated in the reverse direction to liberate the recording medium 501 with the image printed thereon from the platen drum 502, and a blank section having been held by the dampers 504 is cut off with a discharge cutter to form a sheet of recording medium 501 with the image having been recorded therein, but in this system, the paper feed means, recording means, paper discharge means and drive means are independently provided respectively, and operations of each means are controlled by a control circuit.
Because of this configuration, the size of the apparatus as a whole becomes larger, and two or more driving motors and two or more driving mechanisms including those for a paper feed cutter and a paper discharge cutter are required, which in turn makes the cost higher and also makes the size larger. In addition, although a time required for recording can be reduced by performing paper feed and paper discharge at the same time, a complicated control mechanism is required to control the two or more motors and the driving mechanisms synchronously, and a synchronism error easily occurs, and therefore it is necessary to make to some extent lower an operating speed in the operation sequence, and at present it takes about 30 seconds to finish a sheet of recording medium with an image recording apparatus using a normal type of thermal head and ink ribbon.
Further paper waste generated in cutting operations by the paper discharge cutter may sometimes be taken together with the recording medium in the paper discharge side, which may in turn cause the so-called paper jamming.
In the conventional type of image recording apparatus shown in FIG. 1, a two-roll type of ink ribbon having the ribbon cores 507 and 508 both in the feed-out side and in the wind-up side or a ribbon cassette with the two-roll type of ink ribbon incorporated therein is used for the thermal transfer type of ink ribbon 500. When a ribbon core of this ribbon cassette is set in the image recording apparatus, the core 508 in the wind-up side is engaged with a core boss in the wind-up side driven directly or via a clutch mechanism by a motor, while the core 507 in the feed-out side is engaged with a core boss in the feed-out side loading a prespecified torque via a frictional clutch or the like to the core 507 in the feed-out side to give tension to the ribbon.
As clearly shown by the configuration, a torque loaded by the frictional clutch or the like to the conventional type of core 507 in the feed-out side is always kept at a constant level, so that the problems as described below occur.
1. When positioning a recording medium at its starting position, a torque loaded to the core 508 in the wind-up side is required to be larger than that loaded to the core 507 in the feed-out side. Therefore, when a ribbon wound into a roll with many turns is used, a difference between diameters of turns is in inverse proportion to the ribbon tension, so that a adjustment width in setting torques in the wind-up side and feed-out side is very narrow. As a result, sometimes the ribbon gets wrinkled due to shortage of tension to cause mismatching between images with different colors respectively, and further such troubles such as break of the ribbon often occur due to the excessive tension, so that a ribbon with the narrow adjustment width can not be used.
2. When a torque in the feed-out side is set smaller, the problem (1) is solved, but positioning of a recording medium at its starting position can not be performed correctly because of shortage of the tension, or mismatching between images with different colors often occur due to the insufficient tension during printing an image, which makes it impossible to obtain a high quality image.
3. The ribbon tension is adjusted for printing an image, so that the tension is generally excessive for positioning of a recording medium at its starting position, and therefore sometimes the speed for positioning of a recording medium at its starting position may become lower, and the electric energy consumed by a motor for positioning of a recording medium at its starting position may become larger.
As described above, in the conventional type of image recording apparatus based on the conventional technology, as a torque is loaded to the core in the feed-out side with a single frictional clutch by referring to the ribbon tension set for printing an image as a reference, the ribbon tension in operations for positioning at its starting position is generally excessive, so that the excessive tension must be released for positioning the ink ribbon at its starting position. On the other hand, a sufficient tension is required to be loaded to the ribbon for recording a high quality image in printing an image.
In a case of the conventional type of ribbon cassette, ribbon cores are provided also in both the ribbon wind-up side and ribbon feed-out side, and when the ribbon is used to its end, generally the ribbon cassette is disposed as waste together with the used ink ribbon film. A ribbon core generally uses components made from plastics such as vinyl chloride or a paper tube, but when such recent requirements as environmental contamination by industrial and municipal wastes and product cost reduction are taken into considerations, a structure based on the considerations to simplification and the possibility of recycled use is desired. Even when the costs for transporting and packaging the ink ribbon are taken into considerations, it is desirable to abolish a ribbon core in the wind-up side and also to minimize a package of ink ribbon. In addition, when the needs for home use and convenience for general users are taken into considerations, the attachment method should preferably be as simple as possible.
Next, in the conventional type of image recording apparatus, a thermal transfer type of ink ribbon is accommodated in a ribbon cassette, and this ribbon cassette has a protrusion such as a pin or a notch provided to indicates a type of the ribbon, and data concerning the ribbon such as a physical type of the ribbon is read with a detection switch, and in other cases a bar code seal is provided to indicates the ribbon type and the bar code seal is read with a bar code sensor or other appropriate means. When a physical means such as a pin is used to indicate a type of ribbon, the data is limited to a bit number of pins or the like, and a number of sensors are required. For instance, when 256-bit data is to be expressed, at least eight pins and sensors are required. Further, although bar code is used in some cases, a quantity of data expressed by the bar code is limited to at most 1 Kb, and the quantity of data is too small to use the bar code for transmitting information on color materials used in the thermal transfer type of image recording apparatus generally requiring at least 2 Kb for one color. Further, when an expression method based on the conventional technology is employed, the data can not be updated, and a number of remaining ribbon sheets changing from time to time can not be recorded at all. It was also tried to use an IC based on the contact system, but in this case an electrical contact is required, and the reliability is low because of deposition of dust, oil, and other foreign materials on the contact point, so that it has not been used in the thermal transfer type of ribbon cassette.
As described above, there have been several problems in the image recording apparatus based on the conventional technology. One of the problems is that non-uniformity in production of ribbons or a difference in the coloring characteristics due to change of a coloring material is not reflected as data to a ribbon cassette, and in some cases when a ribbon cassette is exchanged with another one, an image with different color tone may be produced with the other image recording apparatus even for the same image data.
The second problem is that, although a residual quantity of a ribbon in a ribbon cassette decreases as production of images goes on, it becomes impossible to detect the residual quantity at a certain point of times. In the conventional technology, detection of the residual quantity of a ribbon is performed by measuring an external form of the ribbon with a sensor or by putting an end marker on a ribbon and detecting the end marker. In this case, for instance, when detection is performed by measuring an external form of a ribbon, it is difficult to accurately check a residual quantity of ribbon having the thickness of only several microns, and an error of around 20% always occurs. When the detection is performed by checking the end marker, it is possible only to check whether the current sheet is a final one or not, and it is at present impossible to print how many sheets of images can be printed. Further, when only the physical detection is performed in the state where a ribbon has been set, if the ribbon has partially been used, a count on a number of sheets of images already print shown by the apparatus is completely different from the actual result. As described above, with the conventional system, how many sheets of images can be printed can not accurately been detected at all.
The present invention provides a thermal transfer type of image recording apparatus in which an image recording medium having been wound up into a roll is cut into a sheet of recording medium; the recording medium cut as described above is wound around a platen drum; coloring matters on the thermal transfer type of ink ribbon are heated by a thermal head and transcribed onto the recording medium; the recording medium with an image already printed thereon is released from the platen drum; and a blank space for being held by the damper on the released recording medium with an image already printed thereon is cut off to provide a finally finished recording medium with an image already printed thereon. A paper feed means in this apparatus feeds out a recording medium would up into a roll state holding it between paper feed rollers, passes the recording medium between a rotary blade and a fixed blade of the paper feed cutter, feeds out the recording medium by a prespecified quantity holding the recording paper with paper feed rollers in the paper feed side onto a slide guide in the paper feed side, fixes a tip of the recording medium with a damper on to the platen drum, and cuts the recording medium with the cutter in the paper feed side into a sheet of recording medium. The image recording means of the image recording apparatus has the configuration in which a platen drum with a damper is positioned in front of the slide guide in the paper feed side of the paper feed means; a movable guide positioned in the entrance side opposite to an exit for the slide guide in the paper feed side and a guide device constituting a fixed guide are provided around this platen drum. The paper discharge means of the image recording apparatus has the configuration in which a paper discharge side slide guide with a paper discharge side roller with an inlet port for receiving a recording medium with an image already printed thereon released from the platen drum when the platen drum is rotated in the reverse direction from its rear side is provided in front of an entrance for the movable guide of the image recording means; a paper discharge side cutter comprising a rotary blade and a fixed cutter is provided at an exit of the slide guide in the paper discharge side; a paper waste patting bar is rotatably provided between the exit of the slide guide in the paper discharge side and the cutter in the paper discharge side; and further a paper discharge roller for discharging the recording medium with an image already printed thereon from inside of the apparatus is provided in the discharge side of the paper discharge side cutter.
With the configuration as described above, size reduction of an image recording apparatus is possible. Further in the image recording apparatus described above, the configuration is allowable in which drive systems for a cutter mechanism, a platen drum, a thermal transfer mechanism, and a paper discharge mechanism are provided in a series and all of the drive systems can be driven by one drive motor.
The image recording apparatus according to the present invention is an image recording apparatus based on a thermal sublimation system in which an ink ribbon in a thermal transfer type of ink ribbon cassette is heated and an image is recorded by transferring the heated color materials onto a recording medium, and this image recording apparatus according to the present invention is characterized in that a tension switch means for setting a tension of the ink ribbon to either a large value or a small value is provided in the ribbon feed-out side and the tension switch means is switched to the large value side when recording an image and to the small value side when the ribbon is positioned to its starting position.
Further the image recording apparatus according to the present invention has also the configuration in which a tension cam switch is attached to a thermal head up/down camshaft for driving the thermal head up and down so that the tension switch means can be switched in synchronism to up/down movement of the thermal head.
The tension switch means comprises a main frictional clutch for setting the tension to the larger side in synchronism to up/down movement of the thermal head and a sub frictional clutch for setting the tension to the smaller side.
The image recording apparatus according to the present invention is characterized in that a ribbon wind-up core is provided in the image recording apparatus side and therefore an ink ribbon based on a simple structure not having a ribbon core in the wind-up side is used. This ink ribbon can easily be loaded on and off.
The image recording apparatus according to the present invention incorporates, in a portion of the ribbon cassette, an IC chip in which a coil and a semiconductor integrated circuit each capable of operating, receiving and transmitting data in a non-contact form when a power is supplied are integrated with each other, so that the image recording apparatus can read, record and rewrite data concerning the ribbon. Because of this feature, a quantity of data, which is not achievable with such methods as bar code, can be read, recorded, and rewritten without causing the problems such as a contact fault which may occur when a contact type of IC chip is used.
When data concerning characteristics of coloring materials applied on a ribbon accommodated in a ribbon cassette is recorded, it becomes possible to correct a difference in the coloring characteristics due to non-uniformity of ribbons generated during production thereof or change of the coloring materials by making use of the availability of a large quantity of data for the image recording apparatus to read the data for providing optimal control.
Further, a residual quantity of a ribbon set in a ribbon cassette becomes smaller as a number of printed images increases, and the residual quantity of a ribbon in a ribbon cassette based on the conventional technology is detected by measuring an external form of the ribbon with a sensor or by previously putting a marker indicating a header or an end of the ribbon and checking the marker, but an accurate residual quantity of ribbon at a given point of time can not be detected at all. With the present invention, however, a number of used ribbon sheets may be written in an IC chip inside the ribbon cassette each time the ribbon is used, so that an accurate residual quantity of ribbon can be detected. Therefore, such a case as that where a ribbon comes to its end and printing is disabled during a printing operation never occurs, and even if a ribbon cassette is exchanged with a new one during a printing operation, the ribbon can be used up to the final one sheet without fail.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.